Sheet feeding apparatus



April 21, 1970 Filed Sept. 5, 1967 F. W. WILSHIN ET AL SHEET FEEDINGAPPARATUS 4 Sheets-Sheet 1 @wiiW Jud: will); add;

W441 ta,- 4 4441 April 21, 1970 F. w. WILSHIN ETAL 3,507,489

SHEET FEEDING APPARATUS Filed Sept. 5. 1967 4 Sheets-Sheet 2 MM 5% wagLu m MpL-GJU A o-1.0mm,

April 21, 1970 Filed Sept. 5, 1967 FIG-13.

F. w. WILSHIN ET AL SHEET FEEDING APPARATUS 4 Sheets-Sheet 5 April 21,1970 F. w. WILSHIN ETAL 3,50

SHEET FEEDING APPARATUS Filed Sept. 5, 1967 4 Sheets-Sheet 4.

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mAMw M 9,4 film M United States Patent U.S. Cl. 271-46 8 Claims ABSTRACTOF THE DISCLOSURE In a sheet-feeding apparatus wherein sheets pass froma high-speed conveyor to a low-speed conveyor, a roller isintermittently operated to press a passing sheet against the low-speedconveyor to ensure its deceleration; means are also disclosed forholding the roller against the sheet and stopping the low-speed conveyorso that gaps between successive sheets can be closed.

This invention relates to sheet feeding apparatus e.g. for use in papercutters and like machines.

In apparatus for feeding sheets, e.g. of paper, high feed speeds areliable to be employed, but at the delivery end of a machine, wheresheets are required to be stacked, it is necessary to decelerate thesheets before they reach the layboy or other stacker if damage is to beavoided and a neat stack formed. It has become a common practice toaccomplish desired deceleration by transferring the sheets from ahigh-speed conveyor to a low-speed conveyor, making provision foroverlapping of the successive sheets as necessary.

The low-speed conveyor need only be short, provided it can be ensuredthat each sheet arriving on the lowspeed conveyor is compelled to adoptthe low speed of said conveyor before leaving it. Most economically andconveniently, the low-speed conveyor is a simple conveyor belt, and anobvious expedient for compelling sheets to conform to its speed is toprovide a roller or belt above and in contact with the low-speedconveyor so that each sheet is held against the belt. Such a simplearrangement is not however satisfactory when sheets arrive on thelowspeed conveyor at high speed as the leading edge portion is suddenlyslowed while the following parts of the sheet are free, hence the sheetstend to buckle undesirably.

According to the invention, we provide sheet feeding apparatuscomprising a high-speed conveyor arranged to deliver sheets insuccession to a low speed conveyor, and a roller for pressing saidsheets against said low-speed conveyor so as to compel the sheets todecelerate to the speed of said low-speed conveyor, in which said rolleris carried on a mounting permitting movement of the roller towards andaway from said low-speed conveyor and said mounting is associated withdrive means arranged to urge said roller towards said low-speed conveyorduring a part of the time required for each sheet to pass said rollerand to hold said roller away from said conveyor at other times.

Conveniently the roller is carried on one or more pivoted members, e.g.bell-cranks, each such member having a bearing for the roller at one ofits ends, the other end of at least one of said members carrying a camfollower riding on a cam profiled to cause desired movement of theroller. The cam or each cam may be a face cam giving a positive drive tothe roller in each direction, but preferably the cam is an edge cam andthe pivoted members are provided with one or more springs arranged tourge each of the followers against the cam or cams. The cam or cams arepreferably so driven that the roller is ice urged towards the conveyoras the trailing portion of each sheet is passing the roller.

Alternatively, the roller may be carried upon a slidable member mountedfor rectilinear movement towards and away from the low-speed conveyor;the cam may then operate directly upon the slidable member carrying theroller, or may act upon a pivoted cam follower engageable with saidrectilinearly slidable member.

Further means may also be provided for urging the roller towards theconveyor, independently of operation of the drive means andsimultaneously stopping the conveyor. This enables a sheet to beadditionally delayed, as is required when overlapping of sheets isdesired and an unusually large gap is detected between successive sheets(e.g. where a sheet has been removed for inspection or because it isfaulty). Such further means preferably includes a pneumatic actuatorwhich may be linked to the mounting for the roller or may operate aseparate roller.

It will be appreciated that apparatus embodying the invention can beoperated satisfactorily when sheets are fed two or more at a time insuperposed relation, as each group of superposed sheets is nippedbetween the lowspeed conveyor and the roller while the roller is urgedtowards the conveyor. The low-speed conveyor preferably comprises aconveyor belt but may alternatively comprise driven rollers protrudingthrough a polished plate.

In order that the invention may be well understood, we will now describepreferred embodiments thereof, illustrated in the accompanyingdiagrammatic drawings in which:

FIGURE 1 is a diagrammatic side elevation of a sheetfeeding apparatus inassociation with a layboy;

FIGURES 2A, 2B and 2C show three alternative arrangements of part of theapparatus of FIGURE 1;

FIGURE 3 is an end view of a fourth alternative arrangement; and

FIGURE 4 shows yet another alternative arrangement, and includes asectional view of a pneumatic actuator.

FIGURE 1 shows apparatus for feeding paper sheets from a cutter 1 to alayboy 2 in which the sheets are to be stacked. 'Said apparatuscomprises an upper belt 3 and lower belt 4 arranged to receive sheetsfrom the cutter 1 and carry such sheets at high speed to the vicinity ofthe layboy 2. The belts 3, 4 may be of substantial length and inassociation with such belts we may provide ancillary equipment, such asinspection devices and means for deflecting faulty sheets, so that thebelts 3, 4 may in practice be discontinuous but this is irrelevant tothe present invention.

The high speed belts 3, 4 terminate at rollers 5, 6 (their delivery end)respectively situated a short distance from the layboy 2 and as sheets 7emerge from between the belts 3, 4 they pass over a fixed bridge member8 onto a slower-moving belt 9 extending to the entrance to the layboy 2,whereafter the sheet enters the layboy and joins a stack forming thereinin conventional manner.

To ensure that each sheet 7 is compelled to decelerate to the speed ofbelt 9 as it passes thereover, a pair of rollers 10, 11 are provided inassociation with said belt 9. Roller 10 is an idler roller lying underthe upper run of belt 9 and roller 11 is also an idler roller and isjournalled in one end of a bell-crank lever 12. The lever 12 is carriedon a pivot shaft 13 and provided with a spring 14 arranged to urge saidlever 12 clockwise (as seen in the drawing) so that a cam follower 15 atits other end is maintained in contact with a cam 16 carried on a shaft17. The shaft 17 is connected by any suitable transmission T to thecutter 1 so that cam 16 revolves in synchronism with the operation ofthe cutter 1, the relative timing and the form of cam 16 being such thatas soon as the trailing edge of each sheet 7 leaves belts 3, 4 but Whilethe trailing part of the sheet is still passing below roller 11, the cam16 moves bell-crank lever 12 anti-clockwise and thus causes roller 11 topress the sheet 7 against belt 9; the sheet 7 and belt 9 are thus nippedbetween rollers 11, 10 and the sheet 7 is forced to conform to the speedof the belt 9 by virtue of the enhanced frictional contact between saidsheet and said belt. Transmission T preferably includes an adjustablecoupling DC to serve as a phasing control, allowing adjusement of thetiming of cam 16 relative to the cutter 1.

The cam 16 is so formed as to maintain the nip between rollers 11, 10for only a short time but once decelerated the sheet 7 naturallycontinues at the speed of be t 9. Bell crank level 12 is not a rigidlever, but its two parts are connected by a spring 18 so as to allow acertain resilience in roller 11 when the latter is engaged with sheets7. The spring-biased lost-motion connection thus provided by lever 12allows for variation in the total thickness of sheets 7.

It will be appreciated that the appearance described, while simple, isyet effective to provide a positive deceleration of the sheets and thussecure their entry into the layboy 2 at the proper speed without anynecessity for stopping the movement of each sheet at any stage before itis actually stacked.

It is a particular advantage of apparatus embodying the invention thatit cannot only deal with single sheets, but functions equally well whenthe cutter 1 (or other apparatus providing the sheets to be fed)produces two or more sheets simultaneously so that when the rollers 11,10 nip, two or more superposed sheets are gripped between the roller 11and belt 9. In the drawing, it will be seen that the sheets 7 are infact shown in superposed pairs. The nip of rollers 11, 10 gives rise toincreased friction between adjacent sheets as well as between thelowermost sheet and the belt 9, so that all the superposed sheets aresimultaneously decelerated to the speed of the belt 9 without change oftheir relative positions. The sheets (or groups of superposed sheets)may be overlapped each with the next, in which case the apparatus may beprovided with devices for maintaining such overlap.

Where overlap is required to be maintained, it is usua ly desirable toprovide means for detection of any gap between successive sheets whichwill prevent proper over lapping, and for this purpose a detector 19such as a photoelectric scanner may be provided near the delivery end ofthe high-speed belts 3, 4. (It will be appreciated that said belts 3, 4may each, as is customary in the art, comprise a number of relativelynarrow belts at spaced positions across the width of the apparatus i.e.normal to the plane of the drawing, and the detetor 19 may be mountedbetween an adjoining pair of said narrow belts).

The detector 19 may be connected to a solenoid 20 (FIGURES 2A, 2B)controlling a compressed air source 21 supplying a pneumatic actuator 22(comprising a cylinder in which a ram is operable) via pipes 23. In thearrangement of FIGURE 2A, there is a bell-crank lever 12a generallysimilar to bell-crank lever 12 (FIGURE 1) but having an extension 12!)beyond the cam follower 15, said extension carrying a block 120engageable by (but not connected to) the ram of pneumatic actuator 22.Thus either the actuator 22 may operate the lever 12a, lifting follower15 away from cam 16, or cam 16 may operate lever 12a, lifting block 12caway from said ram.

In the arrangement of FIGURE 2B, instead of the bellcrank lever there isa rectilinearly slidable member 24 carrying roller 11, the member 24being provided with a return spring 25. A centrally-pivoted cam follower26 has one end engageable with cam 16 and the other end resting betweenthe member 24 and the ram of pneumatic actuator 22.

In both the arrangement of FIGURE 2A and that of FIGURE 2B, whenever thedetector 19 detects a gap between successive sheets such as to requireoperation of roller 11 independently of cam 16, the solenoid 20 causessource 21 to supply compressed air to the pneumatic actuator 22 so thatthe ram of the latter extends; this causes bell-crank lever 12a to turn(FIGURE 2A) or member 24 to be depressed (FIGURE 2B), the cam follower15 or 26 respectively moving away from cam 16, so that in either casethe roller 11 is lowered regardless of the position of cam 16 and isheld in the lowered position until the air supply from source 21 isreversed under control of detector 19 and solenoid 20 so that the ram ofactuator 22 retracts; whenever said ram is retacted as shown, however,it will be apparent that roller 11 will be operated regularly by cam 16as in the arrangement of FIGURE 1.

FIGURE 2C illustrates an arrangement in which provision is made forregular operation only, but the cam 16 is not used. In place of saidearn, i.e. secured to the shaft 17 is a pair of cross-members 27carrying between them a pair of rollers 11a, 11b. It will be seen thatas the shaft 17 is rotated clockwise as indicated by the arrow, therollers 11a, 11b will alternately come into a position corresponding tothe lowered position of roller 11 '(FIG- URES 1, 2A, 2B), and thusproduce the same effect as roller 11 operated by cam 16. Naturally, withthis arrangement, the transmission T (FIGURE 1) will need to have adifferent ratio as the rollers 11a, 11b are effective twice perrevolution of the shaft 17, whereas cam 16 as shown is only asingle-lobe cam giving one operation of roller 11 per revolution.

All three of FIGURES 2A, 2B, 2C also show a further modification, ascompared with FIGURE 1, in that the belt 9 is omitted. In its place is apolished stationary plate 9a through which a roller 10a protrudes, theroller 10a taking the place of roller 10 but being a driven roller,rather than an idler roller; the roller 10a and plate 9a together serveas the low-speed conveyor.

In the arrangement of FIGURE 3, there is again shown a low-speedconveyor of the form just described; as FIG- URE 3 is an end view, itshows three rollers 10a, each protruding through the plate 9a, asrepresentative of a larger number of such rollers located at spacedpositions across the width of the apparatus. However, the arrangement ofFIGURE 3 differs from those already described in that separate means areprovided for retarding sheets regularly and for retarding sheets undercontrol of the detector 19 (FIGURE 1).

Above the first and third of the rollers 10a shown are rollers 11coperated by cams 16 on shaft 17 through rectilinearly slidable members24a tfitted with return springs 25a, i.e. as in FIGURE 2B except thatcam followers 26 and pneumatic actuators 22 are not provided. Thecentral roller 11d, in contrast, has no associated cam 16 or relatedparts, but is carried directly by the cam of a pneumatic actuator 22a;no air connections to said actuator are shown in FIGURE 3 but it will beunderstood that it is connected to a source 21, controlled by detector19 through solenoid 20, exactly as are the actuators 22 of FIGURES 2Aand 2B.

The rollers 10a of FIGURE 3 are carried by a shaft 28 which is drivenvia a clutch 29, said clutch being controlled by detector 19 (FIGURE 1)via a control connection indicated diagrammatically at 30. Also, saidshaft 28 has a brake 31, controlled by detector 19 via a controlconnection 32. Such an arrangement is also provided for rollers 10a ofFIGURES 2A and 2B, and the control connections 30, 32 are such thatwhenever the actuators 22 or 22a are supplied with air, the clutch 29disengages and the brake 31 stops shaft 28, these operations beingreversed whenever the rams of the actuators are caused to retract. Thissecures that anysheet passing under rollers 11c and 11d (or rollers 11)when a gap causes the actuators 22 or 22a to operate is actuallystopped, rather than merely retarded to the speed of the low-speedconveyor. A similar arrangement may be used for stopping the sheet whena belt 9 is used as in FIGURE 1, the clutch and brake then beingassociated with the belt drive.

Lastly, FIGURE 4 shows an alternative arrangement in which cam 16operates a centrally-pivoted cam follower 26a which influences a roller11:: through a pneumatic actuator 22b.

The actuator 22b comprises a fixedly-mounted cylinder 33 in which asleeve 34 is slidable; upper and lower end caps 35, 36 are secured tothe sleeve 34. An inner sleeve 37 is slidable within sleeve 34, and aram 38 is in its turn slidable within the inner sleeve 37. The cylinder33 has three air inlets, a first inlet 39 through which air may besupplied between the outer sleeve and the upper end of the inner sleeve;a second inlet 40 for air supply between the inner sleeve and the ram;and a third inlet 41 for air supply between the outer sleeve and thebottom end of the inner sleeve. A lower closure ring 42 is secured tothe cylinder 33.

Constant air pressures are applied at the inlets 40, 41, respectivelycausing the ram 38 to be urged towards its lowermost position relativeto the inner sleeve 37 and the latter to be held in its uppermostposition relative to the outer sleeve. When the actuator 22b is requiredto lower the roller 11e (i.e. when a gap is detected by the detector 19as before) the inlet 39 is supplied with air at sufficiently highpressure to drive down the inner sleeve 37 taking the ram 38 with itagainst the constant pressure applied through inlet 41; when the rollerHe is required to return, the air supply to inlet 39 is discontinued andthe constant pressure applied through inlet 41 causes the inner sleeve37 (with ram 38) to return to its uppermost position.

The ram 38 is normally maintained in its lowermost position, relative tothe inner sleeve, by the constant air pressure applied above it viainlet 40 but it will be apparent that if anything opposes the descent ofroller 11e (e.g. a number of superposed sheets or, even, an operatorsfinger) then the roller He is not forced down, with possibly damagingresults, with all the power available in the apparatus but will ceasedescending .(i.e. will rise relative to the inner sleeve 37) as soon asthe reaction from whatever opposes the descent of said roller equals theforce exerted on the top of ram 38 by the air pressure applied via inlet40. It will be appreciated that this is a valuable safety feature andprovides automatic adjustment of the apparatus for variations in thenumber and/or thickness of sheets being fed. The arrangement of ram 38to be slidable within sleeve 37, with a constant air pressuretherebetween, provides a pneumatically-biased lost-motion connection tothe roller 112, with a constant limiting thrust as the roller He cannotapply a greater force to the paper (or anything else) under it than thethrust generated by the air pressure acting on the top of the ram 38.

Whenever air pressure is applied via inlet 39, it will naturally tend tolift the outer sleeve 34 as well as causing the inner sleeve 37 todescend. The upper cap 35 of the outer sleeve is therefore maintained incontact with the cam follower 26a. It will be noted that the latter isprovided with an adjustable abutment screw 43 so that the range ofmovement of the outer sleeve 34 may be set as desired.

It will be appreciated that where, as is common, two or more streams ofsheets are being fed along parallel paths into a single layboy, at leastone roller 11 will be provided for each stream of sheets; moreover, insuch a case it is desirable to provide a separate detector 19 andassociated parts for each stream, together with separate control of thedrive to the belt 9 or rollers 10a for each stream, as gaps betweensuccessive sheets are likely to occur at different times in thedifferent streams.

What we claim as our invention and desire to secure by Letters Patentis:

1. Sheet feeding apparatus comprising a high-speed conveyor, a low-speedconveyor arranged to receive sheets delivered in succession by thehigh-speed conveyor, a roller for pressing said sheets against thelow-speed conveyor so as to compel the sheets to decelerate to the speedof said low-speed conveyor, a slide mounting for the roller permittingrectlinear movement of said roller towards and away from the low-speedconveyor, and drive means associated with said mounting, said drivemeans being arranged to urge said roller towards said low-speed conveyorduring part of the time required for each sheet to pass said roller andto hold said roller away from said low-speed conveyor at other times.

2. Apparatus as claimed in claim 1 in which the mounting comprises arectilinearly slidable member carrying the roller, and the drive meansincludes a cam operating directly upon said member.

3. Apparatus as claimed in claim 1, in which said drive means includes apivoted cam follower engageable with the rectilinearly slidable memberand a cam engageable with said cam follower.

4. Apparatus as claimed in claim 1, including further means for pressingthe sheets against the low-speed conveyor independently of operation ofthe drive means and for simultaneously stopping said low-speed conveyor.

5. Apparatus as claimed in claim 4, including a gap detector associatedwith the high-speed conveyor and arranged to control operation of saidfurther means.

6. Apparatus as claimed in claim 5, in which said further means includesa pneumatic actuator linked to the mounting for the roller.

7. Apparatus as claimed in claim 5, in which said further means includesa pneumatic actuator, and a separate roller operated by said pneumaticactuator.

8. Apparatus as claimed in claim 5, in which said further means includesa pneumatic actuator and said drive means includes a cam and a camfollower associated with said cam, said actuator being arranged tofunction as a pneumatically-biased lost-motion connection between saidcam follower and the roller.

References Cited UNITED STATES PATENTS 567,264 9/ 1896 Child 27l46985,014 2/1911 Dexter 27l46 1,142,786 6/1915 Kneppler 27l46 3,034,7805/1962 Stelling 27 l-46 X 3,315,956 4/1967 Lyman 27 I46 FOREIGN PATENTS1,243,966 6/1967 Germany.

EDWARD A. SROKA, Primary Examiner U.S. Cl. X.R. 27l-76

